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Search for "reactions" in Full Text gives 3177 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts
Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76
- power (E*red up to 1.5 V) can be classified as a bimodal photocatalyst. This type of molecule is capable of driving both oxidative and reductive reactions, thereby offering significant versatility to achieve photocatalytic transformations. To our delight, molecule 5a possesses a promising E*ox =−1.89 V
- photoredox properties with TBA, its analog 5H-dibenz[b,f]azepine (IMD), and common nitrogen donors. The excited state redox potentials of these compounds suggest their suitability for challenging photocatalytic reactions through oxidative and reducing quenching cycles. TBA showed a well-balanced redox window
- negatively impact photocatalytic activity, showing similar results in some of the benchmark reactions carried out during this analysis. Our findings suggest that antiaromatic compounds like TBA could replace traditional nitrogen donors in PCs, offering good redox potentials and competitive photophysical
Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines
Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74
- procedures and harsh reaction conditions, resulting in limited substituent and scaffold diversity [18][19]. In this regard, multicomponent reactions (MCRs) have gained increasing attention for their operational simplicity, efficiency, robustness, atom economy, and potential for diversity-oriented synthesis
- , propiolic acids 8a–d, and isocyanides 4a–e. By conducting the reactions in methanol at 70 °C, we obtained the desired Ugi adducts 15a–x in fair to good yields of 26–72% allowing for the variation of substituents across all components of the U4CR (Scheme 2). Notably, the Ugi reaction toward substrate 15a
- reduction with LiAlH₄, which led to a further decrease in the degree of unsaturation of the pyrazolodiazepine core, while the more sterically hindered exocyclic amide moiety remained intact. However, both reactions were accompanied by partial epimerization, and careful kinetic control was therefore required
Recent advances in controllable/divergent synthesis
Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73
- alkyldiamines proceeded with solvent-independent regioselectivity, exclusively furnished [2 + 2] macrocyclic adducts. Strikingly, when 37 was combined with 2,2’-oxybis(ethylamine) (38), the reaction pathway exhibited pronounced solvent dependency. Reactions in methanol, ethanol, or chloroform selectively
- -García and Fernández-Rodríguez reported on the practicality of metal-free BCl3-catalyzed borylation cyclization reactions in synthesis (Scheme 16) [45]. Biphenyl-embedded 1,3,5-trienes-7-yne compounds 58 react with BCl3 under catalyst-free and additive-free conditions to form novel polycyclic boronated
- (such as indole substrates), Int-79 is more stable at −78 °C, favoring the formation of the mono-insertion product 86. In 2022, Wu and colleagues reported a novel methodology for constructing α-ketoamides 90 or 92 and amides 91 through copper-catalyzed dicarbonylation and monocarbonylation reactions
Data accessibility in the chemical sciences: an analysis of recent practice in organic chemistry journals
Beilstein J. Org. Chem. 2025, 21, 864–876, doi:10.3762/bjoc.21.70
- for researchers to report the outcomes of low/no-yielding reactions that describe a broad chemical space [31][75]. Mandates for deposition, standardized data formats, and centralized repositories are all necessary to enable compliance with FAIR principles [76]. AI is having a major impact on many
Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters
Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69
- , and control reactions support sensitization, enabling an intramolecular [2 + 2] cycloaddition to be realized accessing 3D bicyclic fragments containing a boron handle. Keywords: boron; catalysis; [2 + 2] cycloaddition; energy transfer; photochemistry; Introduction The strategic use of a photon to
- identify a suitable catalyst and boron residue, while control reactions and mechanistic studies support the proposed sensitization. The platform enables direct access to mono- and vicinal cyclobutylboronic esters that could be effectively derivatized to demonstrate their potential in synthesis. Results and
- process (Figure 2B) [19]. In a bid to translate sensitization reaction probes to meaningful synthetic transformations, conventional intermolecular [2 + 2] cycloaddition reactions were initially trialled (Figure 3A). Preliminary reactions using styrene or methyl acrylate were unsuccessful, with no [2 + 2
Chitosan-supported CuI-catalyzed cascade reaction of 2-halobenzoic acids and amidines for the synthesis of quinazolinones
Beilstein J. Org. Chem. 2025, 21, 839–844, doi:10.3762/bjoc.21.67
- in organic transformations [22][23][24], we intended to investigate the use of chitosan-supported copper as a catalyst for the synthesis of quinazolinones from 2-halobenzoic acids and amidines under mild reaction conditions (Scheme 1c). Results and Discussion The initial reactions commenced with 2
- obtained (Table 1, entry 19). With the optimized conditions in hand, we explored the substrate scope of the CS@CuI-catalyzed cascade reactions of 2-halobenzoic acids (including 2-iodobenzoic acid and 2-bromobenzoic acid) with amidines (Scheme 2). Initially, when the amidine substituent (R2) is a methyl
- group, we investigated the reactions with various substituted 2-halobenzoic acids. The reactivity of 2-iodobenzoic acid derivatives (3a–d, 90−96% yields) was higher than that of 2-bromobenzoic acid derivatives (3a–d, 57−73% yields), the electronic properties of the substituents on the benzene ring had
Synthesis and photoinduced switching properties of C7-heteroatom containing push–pull norbornadiene derivatives
Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64
- synthesized (Scheme 1, bottom). In contrast to the previously synthesized large library carbon-based NBDs [40], only a few heterocyclic derivatives were successfully isolated. During the monitoring of additional reactions attempting to reproduce the literature scope, in most cases traces of new NBD species
Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers
Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63
- -system configuration promotes selective functionalization, enabling the synthesis of various complex products through a single transformation [17][18][19]. Therefore, allenes have become versatile intermediates in numerous transition-metal-catalyzed reactions [20][21]. Despite extensive studies on the
- scope for the formal hydrocyanation with 1,1-disubstituted and 1,1,3-trisubstituted allenes was examined (Scheme 3). All reactions were performed in the presence of 5 mol % IPrCuCl to generate the allylaluminum reagents in situ, followed by cyanation at room temperature for 30 min. This method
- converted to the desired nitrile 5g in high yield. Gram-scale reactions were conducted using allenes to demonstrate the practical applicability of this hydrocyanation method (Scheme 5). Allene 1q (1.04 g, 7.2 mmol) and allene 4b (1.08 g, 6.0 mmol) were effectively transformed into nitrile products 3q and 5b
Recent advances in the electrochemical synthesis of organophosphorus compounds
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- efficiency of reactions [14][15][16][17][18][19][20][21]. Organophosphorous compounds are essential materials with broad applications in medicinal chemistry, synthesis, agriculture, as ligands, and intermediates to prepare complex compounds. Due to their importance, scientists have introduced many studies in
- generates an electric current. Some of its applications include batteries (e.g., lithium-ion batteries) and fuel cells. These cells are usually in a divided state. Electrolytic cell These cells require an external voltage to drive chemical reactions. They use electrical energy to carry out a non-spontaneous
- reduction occur in separate compartments, separated by a diaphragm or salt bridge, to prevent reactant mixing and improve efficiency (e.g., Daniel cell). However, in undivided cells, both reactions occur in a single compartment without separation, resulting in a more straightforward design but potentially
New advances in asymmetric organocatalysis II
Beilstein J. Org. Chem. 2025, 21, 766–769, doi:10.3762/bjoc.21.60
- cycloaddition reactions [1][2][3][4]. The history of scientific discoveries, however, is rarely defined by single specific dates that can unambiguously be connected to the discoveries. Instead, the chronology often seems to be quite convoluted but also ultimately more interesting, as can also be seen for
- -catalyzed reactions and biocatalysis. In the past 25 years, organocatalysis has grown rapidly into a broad area of research, with industrial applications now being developed [16]. The usefulness of any idea or methodology is ultimately often measured by its applications. The robustness, reliability, as well
- organocatalytic cycloaddition reactions of unsaturated imines. A broad variety of activation modes, as well as catalyst structures, was covered and found to be useful in affording a diverse array of chiral N-heterocycles [27]. In my group, we recently became interested in atroposelective catalytic syntheses
Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones
Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59
- through calcium catalysis [8][9][10]. Asymmetric synthesis has also been achieved via, e.g., 1,4-addition and [3 + 2] cycloaddition of 3-tetrasubstituted oxindoles with a calcium Pybox catalyst [11][12], or through enantioselective Friedel–Crafts and carbonyl–ene reactions [13]. Since the pioneering
- in elucidating the mechanism by which these bifunctional compounds act as powerful catalysts [21][22][23][24][25][26][27][28][29]. Since Ishihara disclosed the crucial role of calcium in many purportedly purely organocatalytic BINOL phosphate-catalyzed reactions [30][31], several asymmetric synthesis
- that might similarly occur also in related addition reactions of alkenes, for example. After 11E had reacted with TMSCN, adduct 13 forms, 3.8 kcal·mol−1 more stable than the competing unreactive adduct obtained from "Z" conformation. Outside from the catalytic cycle, 12 could be further hydrolyzed in a
Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion
Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57
- 3αMan 5, first order reactions were assumed with the rate constants k5, k7, and k6 (Figure 2C). In order to determine the half-lifes τ1/2 and activation energies Ea of the photoswitching units comprised in the homobivalent glycocluster 6αMan3αMan 2, the decay of the metastable ZZ isomer to the
Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA
Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56
- 14 (Figure 2). Synthesis of a bifunctional Pepper dye Encouraged by the efficient attachment of the bromo- and mesyloxypropyl-modified HBC fluorophores to the Pepper aptamer, we generated a bifunctional HBC ligand with a second handle that is available for bioorthogonal reactions. The original
Origami with small molecules: exploiting the C–F bond as a conformational tool
Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54
- angle widening in gem-difluoroalkanes is seen in the rates of the ring-closing methathesis reactions of the dienes 8 and 9 (Figure 3) [25]. The fluorinated substrate 9 cyclises much more efficiently than the non-fluorinated substrate 8, and this was attributed to a thermodynamic effect, i.e., a more
- -membered ring of pyranoses. However, it must be remembered that pyranoses are reactive molecules that can undergo, e.g., glycosylation, and it emerges that fluorine can play a much more significant conformational role during the dynamics of such chemical reactions [125][126][127][128][129][130
- ]. Glycosylation reactions (e.g., 63 → 65 and 64 → 66, Figure 9) proceed via an oxocarbenium intermediate. If fluorine is located at C-2, an electrostatic attraction might be expected between the partially negative fluorine and the positively charged C=O+ moiety, and this interaction would favour one of the half
Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra
Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53
- compounds, F8PIC and F8FUL, were obtained through the Wittig-reaction and Mallory-photoreaction sequence (Scheme 2). Thus, reactions between phosphonium salt 5 and specific aldehydes, 10 and 13, followed by photolysis in the presence of I2 and O2, respectively, afforded F8PIC (57%) and F8FUL (52%). F87PHEN
Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex
Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52
- fluorinated amino acids that can be synthesized from a single starting material is a unique feature of this method, making it an important cornerstone of fluoropeptide chemistry. Experimental General information Air- and hydrolysis-sensitive reactions were carried out under exclusion of air and water in
- Schlenk vessels at a Schlenk unit/oil pump vacuum under nitrogen atmosphere. The stated reaction temperatures are the respective values of the silicone oil heating bath. All reactions were stirred with an electric magnetic stirrer. 1H, 13C, and 19F NMR spectra were measured at room temperature with a JEOL
Recent advances in allylation of chiral secondary alkylcopper species
Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51
- attention due to their unique properties in stereoselective allylic substitution. This review highlights recent advances in copper-catalyzed asymmetric allylic substitution reactions with chiral secondary alkylcopper species, encompassing several key strategies for their generation: stereospecific
- substitution reactions began to develop with the groundbreaking work of Takeuchi and Kashio, and subsequent research has revealed that iridium catalysts behave quite differently from their palladium counterparts [18]. The most notable distinction lies in their contrasting regioselectivity patterns. Palladium
- -catalyzed allylic substitution reactions [20]. To address these limitations, copper-catalyzed processes have emerged as a promising alternative. Copper-catalyzed allylic substitutions are distinguished by their unique inner-sphere mechanistic pathway, which enables the incorporation of hard, non-stabilized
Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters
Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50
- [7][8] (Figure 2, reactions 1 and 2, respectively). Results and Discussion N-Acetylamino malonic acid monoester 9a possessing a tosyl-protected tethered amine was selected as a model substrate for the development of the intramolecular amidation under Hofer–Moest conditions. The acid 9a was prepared
- was not extracted from background-corrected voltammograms. All CV graphs are plotted using IUPAC polarographic convention. Selected examples of α,α-disubstituted cyclic amino acids in drug design. Electrochemical decarboxylative amination reactions. A) Cyclic voltammograms of 6a and 9a at 3 mM and 6
Photocatalyzed elaboration of antibody-based bioconjugates
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
- stability, and/or a shorter ADC half-life [14]. Optimization of the drug/antibody ratio (DAR) and payload distribution/location thus becomes significant for ideal ADC design. Given the complexity of biological macromolecules, there are inherent limitations in terms of the types of reactions that can be used
- to modify them. Reactions must be carried out at or near ambient temperatures and near-neutral pH. Aqueous media is often required to solubilize the substrates and/or to prevent denaturation, and reactions are normally carried out under very dilute (micromolar) conditions. As importantly, the highly
- covalent bioconjugation. Effective bioconjugation has been dramatically facilitated by the development of robust bioorthogonal reactions, which has revolutionized the field of chemical biology [17]. A bioorthogonal reactive group can be introduced into proteins via direct chemical coupling on specific
Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities
Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48
- derivatives 2–8. Reagents and reactions conditions: a) (CH3CH2)3N/DMAP and methacryloyl chloride in CH2Cl2; b) (CH3CH2)3N/DMAP and cinnamoyl chloride in CH2Cl2; c) (CH3CH2)3N/DMAP and 4-bromobenzoyl chloride in CH2Cl2; d) (CH3CH2)3N/DMAP and trans-2-methyl-2-butenoyl chloride in CH2Cl2; e) (CH3CH2)3N/DMAP and
Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions
Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47
- ] and has been used in syntheses of natural products containing aryl quaternary carbon centers [9][10]. Unlike the intramolecular alkylation strategy of a phenol derivative, which can only be applied in basic dearomatization reactions, our approach using an α-iodophenol ether as precursor of the
- two allyl groups into the product, thus avoiding the challenges associated with allyl formation reactions. The chosen synthetic route towards (±)-simonsol C is shown in Scheme 3. Starting with magnolol (11), one of the phenol groups was selectively protected by controlling the equivalents of MOMCl and
- were optimized to achieve product 20 with 85% yield, minimizing potential side reactions. The subsequent dearomatization step is crucial for the construction of the cyclohexadienone unit. Oxidation of compound 20 with PIDA in trifluoroethanol, the original phenol was converted into a quinone moiety
Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water
Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46
- methylated amino acids and carbamates (65–75%) [9] or cyanobenziodoxolone (CBX) (54–88%) [10]. Reactions using 1,2-diaza-1,3-dienes, amines, and isocyanates (47–76%) [11], as well as α-amino amides with triphosgene or carbonyldiimidazole (CDI) (41–80%) [12], have also been explored. Other strategies include
- copper(I)-catalyzed reactions (48–71%) [13] and the four-component Ugi reaction [14] yields 48–71% and 27–67%, respectively. In addition, pyroglutamates with isocyanates, which provide exceptionally high yields (97–99%) [15], and dipeptides have been utilized in triflate-activated Mumm’s rearrangement
- substrate reactivity, minor side reactions, or minor losses during microwave irradiation. The remaining part may be caused by factors such as slight volatilization or incomplete conversion under specific use conditions. We found the synthetic procedure facile as the less polar hydantoin products (H2a–c, H2e
Formaldehyde surrogates in multicomponent reactions
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- /bjoc.21.45 Abstract Formaldehyde emerges as a cornerstone in multicomponent reactions, mainly prized for its robust reactivity. Yet, alongside these beneficial traits, this highly reactive C1-building block raises concerns, primarily regarding its toxicity. One notable issue is the challenge of
- controlling the formation of undesired byproducts during its reactions. This review explores alternative C1-building blocks that serve as surrogates for formaldehyde, aiming to mitigate some of the challenges associated with its use in multicomponent reactions. By identifying these alternatives, toxicity
- concerns and improved reaction control can be addressed, paving the way for more efficient and sustainable synthetic methodologies. Keywords: cascade reactions; formaldehyde surrogates; green chemistry; heterocycles; multicomponent reactions; Introduction Organic chemistry is a mature discipline that has
Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles
Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44
- structure of used N-nucleophile various types of a heterocyclic system can be obtained. A large number of examples of reactions with substituted amines have been reported in the literature. Generally, this process includes opening of the furanone ring followed by cyclization to the pyrrolone moiety [6][7][8
- pyrrolones such interaction can lead to pyridazinone systems [10][11]. Despite on the plenty of reactions with nitrogen-containing nucleophiles there is only one example of recyclization using furanone with a carbonyl group at position 3 (Scheme 1a, previous work) [6]. However, no work on this type of
Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt
Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43
- of its unique interaction in organic synthesis. Chiral halonium salts have been found to have strong halogen-bonding-donor abilities and work as powerful asymmetric catalysts. Recently, we have developed binaphthyl-based chiral halonium salts and applied them in several enantioselective reactions
- developed chiral halonium salts and applied them to asymmetric reactions such as vinylogous Mannich reactions of cyanomethylcoumarins 6 with isatin-derived ketimines 7 [33][35] and 1,2-addition reaction of thiols to ketimine [34], which formed the corresponding products 8 in high yields with high to
- tetrasubstituted carbon stereogenic centers [42][43][44][45][46]. In 2011, Shibasaki, Matsunaga and co-workers reported strontium or magnesium-catalyzed stereodivergent asymmetric Mannich reactions of an α-isothiocyanato ester with ketimines, which provided the products in excellent yields and
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